1. Field of the Invention
The present invention relates to a battery charging cradle and mobile electronic device, where the mobile electronic device is placed on the battery charging cradle so that electric power is carried from the battery charging cradle to the mobile electronic device by an electromagnetic induction effect to charge a rechargeable battery incorporated in the mobile electronic device.
2. Description of the Related Art
A battery charging cradle and mobile electronic has been developed in which electric power is carried from a primary coil to a secondary coil by the effect of an electromagnetic induction to charge a rechargeable battery. Refer to Japanese Patent Laid-Open Publication No. H09-63655 (1997) and Japanese Utility Model Registration No. 3011829.
Described in Japanese Patent Laid-Open Publication No. H09-63655 (1997) is a structure in which the primary coil excited by an AC power source is incorporated in the battery charging cradle and the secondary coil being electromagnetically coupled to the primary coil is incorporated in a battery pack. The battery pack also incorporates a circuit in which an alternating current induced to the secondary coil is rectified and supplied to charge the rechargeable battery. In accordance with such structure, the battery pack is placed on the battery charging cradle so that the rechargeable battery incorporated in the battery pack can be charged in a non-contact state.
Also described in Japanese Utility Model Registration No. 3011829 is a structure in which the battery is incorporated at the bottom of the mobile electronic device, and further a secondary-side charging adaptor is subjacently provided so that the secondary coil and a charging circuit are incorporated in the secondary-side charging adaptor. Also described is a structure that the primary coil being electromagnetically coupled to the secondary coil is provided to the battery charging cradle. The mobile electronic device connected to the secondary-side charging adaptor is placed on the battery charging cradle, and the electric power is carried from the primary coil to the secondary coil to charge the rechargeable battery incorporated in the mobile electronic device.